1 Conceptual understanding of electrical circuits in secondary vocational engineering education: Combining traditional instruction with inquiry learning in a virtual lab Bas Kollöffel and Ton de Jong University of Twente, The Netherlands Abstract Background Traditionally, engineering curricula about electrical circuits use textbook instruction and hands-on lessons, which are effective approaches for teaching students terms and definitions, the procedural use of formulas, and how to build circuits. However, students often lack conceptual understanding. Purpose (Hypothesis) The aim of this study was to find out how the acquisition of conceptual understanding can be facilitated. It was hypothesized that adding an extra instructional approach in the form of inquiry learning in a virtual lab would be more effective than relying on traditional instruction alone. Design/Method Students from secondary vocational engineering education were randomly assigned to one of two conditions in a quasi-experimental study. In the traditional condition the traditional curriculum was supplemented with additional (computer-based) practice. In the virtual lab condition the traditional curriculum was supplemented with inquiry learning in a virtual lab.
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Conceptual understanding of electrical circuits in secondary vocational engineering
education: Combining traditional instruction with inquiry learning in a virtual lab
Bas Kollöffel and Ton de Jong
University of Twente, The Netherlands
Abstract
Background
Traditionally, engineering curricula about electrical circuits use textbook
instruction and hands-on lessons, which are effective approaches for teaching
students terms and definitions, the procedural use of formulas, and how to
build circuits. However, students often lack conceptual understanding.
Purpose (Hypothesis)
The aim of this study was to find out how the acquisition of conceptual
understanding can be facilitated. It was hypothesized that adding an extra
instructional approach in the form of inquiry learning in a virtual lab would be
more effective than relying on traditional instruction alone.
Design/Method
Students from secondary vocational engineering education were randomly
assigned to one of two conditions in a quasi-experimental study. In the
traditional condition the traditional curriculum was supplemented with
additional (computer-based) practice. In the virtual lab condition the
traditional curriculum was supplemented with inquiry learning in a virtual lab.
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Results
The results showed that students in the virtual lab condition scored
significantly higher on conceptual understanding (Cohen’s d = 0.65) and on
procedural skills (d = 0.76). In particular, students in this condition scored
higher on solving complex problems (d = 1.19). This was true for both
complex conceptual and complex procedural problems.
Conclusion
The observation that students in the virtual lab condition not only acquired
better conceptual understanding but also developed better procedural skills
than students in the traditional condition gives support for the idea that
conceptual understanding and procedural skills develop in an iterative fashion.
2008; Jaakkola et al., 2010; Jaakkola et al., 2011; Zacharia, 2007). These studies focused on
elementary school children (Jaakkola & Nurmi, 2008; Jaakkola et al., 2010; Jaakkola et al.,
2011), pre-service elementary school teachers (Başer & Durmuş, 2010), and university
students (Farrokhnia & Esmailpour, 2010; Finkelstein et al., 2005).
In the current study we focus on a different type of students, namely students from
secondary vocational engineering education. Vocational education is more concrete in nature
compared to general types of education. In vocational education students are trained for
clearly defined professions or tasks (e.g., becoming mechanics, electricians) (Slaats,
Lodewijks, & van der Sanden, 1999). In the Netherlands, an achievement test known as the
‘CITO-test’ (the Central Office for Standardised Testing) is administered to all pupils at the
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end of their primary education. On the basis of their test scores the pupils are tracked into
either pre-vocational education or general (higher or pre-university) education. A little more
than 60% of the students are tracked into pre-vocational education (12- to 16-year-olds) and
then secondary vocational education (16- to 20-year-olds) (Meijers, 2008). Inquiry learning is
often assumed to be too demanding for these students, because it requires them to adopt a
scientific approach. Vreman-de Olde (2006) characterizes students in secondary vocational
training as ‘do-ers’, who have a visual orientation and who are mostly interested in the
practical application of their knowledge. They learn by experience and have difficulty with
abstract theoretical models and methods (Slaats et al., 1999). In particular, these students find
the domain of electricity to be abstract. Vreman-de Olde (2006) suggests that using realistic
visualizations in computer simulations (or virtual labs) can support these students in
connecting reality and theoretical concepts. Working with real laboratories is also a necessity
for these students, because they will work with similar equipment in their professional lives.
Therefore, in the current study we did not replace the practical lesson with a real laboratory
but instead gave students additional lessons in a virtual lab.
The main question addressed in the current study is: how can the acquisition of conceptual
understanding be fostered in electricity instruction that occurs in the context of secondary
vocational engineering education? The current study compares two experimental conditions:
one condition in which students followed traditional instruction supplemented with inquiry
learning within a virtual lab, and one condition in which students followed traditional
instruction only (supplemented with additional traditional (computer-based) practice). The
lessons involved were an integral part of a complete electricity curriculum (including both
textbook and practical lessons) in the context of intermediate level vocational engineering
training.
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Method
Participants
In total, 56 students in intermediate level vocational engineering training participated, all boys
(no female students were enrolled in the engineering courses). The study was approved by the
school board and the participants’ parents. As will be further explained in the next section
there were two conditions, the traditional condition and the virtual lab condition. Thirteen
participants dropped out: four dropped out of school during the period in which the
experiment took place (one in the traditional condition and three in the virtual lab condition);
four missed more than half of the sessions (two in the traditional condition and two in the
virtual lab condition); and five were unable to attend the post-test session (two in the
traditional condition and three in the virtual lab condition). The ages of the 43 remaining
students (23 in the traditional condition and 20 in the virtual lab condition) ranged from 16 to
22 years old (M = 19.17; SD = 1.39).
Design
A between-subjects design was used in the experiment, with the Instructional method
(traditional instruction plus extra computer-based practice (traditional condition) versus
traditional instruction plus inquiry learning within a virtual lab (virtual lab condition)) as the
independent variable. Participants were randomly assigned to either the traditional condition
or the virtual lab condition. Students in both conditions followed the same curriculum, the full
regular electricity curriculum. This curriculum in which the experiment was embedded
contained the following courses: a textbook-based course, “Electricity Theory”, and two
practical courses, “Measuring Electricity” and “Workplace Practice”. The courses in the
curriculum lasted three months or more. The time span of the experiment was nine weeks,
with one session every week. These nine sessions formed a relatively small part compared to
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the entire electricity curriculum, but the experiment only aimed to cover the period during
which simple DC circuits were treated in the regular curriculum. In the traditional condition,
the traditional instruction was supplemented with additional practice (based on traditional
instruction) on topics treated in the main curriculum. In the virtual lab condition, the
traditional instruction was supplemented with inquiry learning in a virtual lab, also on the
topics treated in the main curriculum. Except for these nine sessions, all courses and activities
were the same for all participants.
Learning environments
The regular curriculum that the students follow includes topics such as energy sources,
resistance, circuits, Ohm’s Law, Kirchhoff’s Laws, alternating current, and magnetic fields. In
this curriculum students have textbook and practical (lab) lessons. The emphasis in the
textbook lessons is on facts, definitions, formulas, and procedural skills (calculating
parameters such as voltage, current, resistance, and power); in the practical lessons students
practice building electrical circuits and performing electricity measurements in these circuits.
Two books are used: a textbook (Frericks & Frericks, 2003) in which facts, definitions, and
formulas are presented and procedures are explained, and an exercise book (Frericks &
Frericks, 1998) with chapters that correspond to the chapters in the textbook. These chapters
briefly repeat the topics treated in the textbook, provide more in-depth explanations of
procedures, and offer questions (about facts and definitions) and assignments in which
students are required to calculate parameters. The experiment covered part of the topics
treated in the regular curriculum, namely electrical circuits (series, parallel, and mixed
connections), Ohm’s Law, and some elements of Kirchhoff’s Laws. Two computer-based
learning environments were used in the experiment, one for each condition.
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Learning environment used in the traditional condition
The traditional condition included use of a computer-based learning environment that was
developed and produced by the same company that published the textbook and exercise book
described above. The software was meant as additional practice material (although the
participating school did not use this software in the regular curriculum). The software offered
a brief summary and a series of exercises for each chapter of the textbook and exercise book,
mainly calculation exercises, but also some insight questions (measured by means of multiple
choice items). After completion of each exercise, students received feedback about the
correctness of their response as well as an explanation of the correct answer. At the end of
each chapter the system informed the student about the percentage of correct responses for
that chapter.
Learning environment used in the virtual lab condition
Participants in the virtual lab condition were provided with a virtual lab-based inquiry
learning environment. This was created by the authors with SIMQUEST authoring software
(de Jong et al., 1998; Swaak & de Jong, 2001; van Joolingen & de Jong, 2003). The virtual
lab environment presented photographic images of equipment used in the school’s practical
(lab) courses about electricity (see Figure 1).
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Figure 1. Screen dump of virtual lab
In the virtual lab environment the students were presented with electrical circuits. They could
add or remove electrical components (e.g., light bulbs, resistors, LED’s), adjust the voltage,
and perform measurements using virtual measuring equipment to measure (changes in)
voltage across components and the strength of the current flowing through different parts of
the circuit. The images of real equipment made the virtual lab highly realistic.
As indicated in the introduction, students need instructional guidance in order to make
inquiry learning within a virtual lab effective. In the current study students were provided
with assignments that were integrated within the virtual lab environment, and that were
designed to structure their experimentation processes. Such assignments have been found to
be a successful type of instructional guidance in inquiry learning (Swaak, van Joolingen, & de
Jong, 1998). In the current study, these assignments had the following structure: first, the
student was asked to predict the outcome of a change in a circuit,e.g., “In a series connection
there is one component, a light bulb (6V/3W). The voltage applied across this bulb is 6V.
Suppose a second bulb is added to the connection. What will happen to the voltage across the
first bulb (all else being equal)?”. This part of the assignment was meant to activate prior
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knowledge and to have students articulate their own, idiosyncratic conceptions (or
misconceptions) about the domain. Then the participants could use the virtual lab to
experiment, that is, to collect empirical data, and make observations that would help them to
find out what really happens in the situation described in the first step. After the second step,
the participants were asked to reflect upon the correctness (or incorrectness) of their initial
prediction and to draw conclusions on the basis of their observations in the virtual lab.
Knowledge measures
Two knowledge tests were used in the experiment: a prior knowledge test and a post-test. The
prior knowledge test was an entrance test that contained 27 items and aimed at measuring
(possible differences in) the prior knowledge of the students. The post-test contained 19 items
and was meant to measure the effects of instructional method on learning outcomes. The prior
knowledge test contained 14 conceptual and 13 procedural items. The post-test contained 14
conceptual items and 5 procedural items. Because the depth of understanding required to
answer problems depends on their level of complexity, we included both simple and complex
items on the post-test.
Conceptual and procedural items
In the introduction it was argued that a proper conceptual understanding enables students to
reason about potential differences and the flow and the intensity of current (Cohen, Eylon, &
Ganiel, 1983; Frederiksen, et al., 1999; Streveler, et al., 2008). Therefore, the conceptual
items on the test required participants to reason about the behavior of current and potential
difference in various DC circuits, including series, parallel, and mixed connections. (At this
stage, the curriculum and the textbook treated resistance as a constant.) In some conceptual
items participants were given two circuits (e.g., one circuit with two light bulbs in a series
connection, and one circuit with two light bulbs in parallel) and then they had to reason about
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how a specific variable (e.g., current) would behave in the different circuits. In other
conceptual items participants were given a circuit in which a certain change took place (e.g.,
turning a switch on or off). Then they had to reason about how this change in one parameter
would affect other parameters. An example of a conceptual item is shown in Figure 2.
Given the circuit displayed above. Light bulb L1 is shining. Peter is measuring the current at ITOT. When switch S is turned on, Peter notices that the current remains unchanged. Why is that?